Indicator for suction cleaners



May 23, 1939. H. B. WHITE INDICATOR FOR SUCTION CLEANERS Filed Sept. 28, 1936 ATTORNEY Patented May 23, 1939 UNiTED STATES PATENT OFFICE 2,159,112 INDICATOR FOR SUCTION CLEANERS f Harry B. White, Canton, Hoover Company, Nort poration of Ohio Ohio, assignor to The h Canton, Ohio, a cor- Application September 28, 1936, Serial No. 102,897

8 Claims.

This invention relates to improvements in suction cleaners and more particularly to devices mediate emptying thereof.

10 The object of the present invention is to provide an lmproved construction for a pressure indiof the suction cleaner shown in Figure 1, with a portion of-its top wall broken away to show the go mounting of the bag pressure indicator.

Figure 3 is an enlarged view in front elevation of the bag pressure indicator removed from the cleaner and 4 Figure 4 is a view in vertical section taken on 5 line 4 4 of Figure 3.

Referring to Figures 1 and 2, the cleaner to which the invention is especially adapted, consists of a main body or casing I having a transversely extending nozzle portion 2 at its forward 3 end and supporting at its central portion a domelike cover 3 which houses a motor fi having direct driving connection with a fan located in a fan chamber immediately below the motor ca sing and communicating with an exhaust outlet having a`A large rearwardly opening flanged connection 5. A dust bag 6 is removably attached to the outlet connection through the medium of a r'netal ring 'I having notched ears 'I a, 'Ia engaging a pair of bolts 8, 8 mounted at opposite sides of the anged connection 5. v

'Ihe cleaner is mounted upon wheels 9 located forwardly-and rearwardly of the casing I, and is maneuvered through the medium of a handle not shown herein, except for a. portion of the bail I0 forming .the lower end of the handle, and having pivotal connection with the casing I.

AReferring to the pressure indicator, the same is located adjacent the rear end of the casing I and is supported upon the top wall Ia of said casing between the motor 4 and the outlet connection 5, and enclosed by the rear portion of the cover 3. In its general aspects, the indicator in the opposite direction by 10 bracket II, preferably a sheet metal stamping,

of the cleaner as shown in Figure 1, the lowerscrews I2 passing through one or more ears I3 stamped from the bottom web II c of the bracket II.

Firmly held by the bracket II and within the space included by the transverse webs IIb and IIc and its open end facing forwardly, as clearly adjacent edges of the bracket webs I Ib and IIc,

likewise project forwardly a short distance beyond I6 with its ends passing through holes punched in the tips of said ears I5. This pin supports a hinged or swinging plate I1 having a pair of lugs I'Ia, I'Ia, formed at the extremities of its top edge and bent at right angles to form ears through which the pin I6 passes. As clearly shown in Figure 4, the upper edge portion of the plate I'I 55 is spaced outwardly from the open end of the cup member I4 but immediately below the hinged with the open end of said `cup member I4. Now, integral with the hinged plate I1, and located at one of its lower corners is a signal arm I8, extending a short distance below the base of the supporting bracket II, and thencei bent outwardly at substantially right angles, terminates in a rounded end bearing an upwardly facing target I8a of a bright color, such as red, at its center.

Housed within the metallic cup member I4, is an expansible bellows member I9 of comparatively thick flexible material such as rubber or rubber impregnated fabric having a general cylindrical form and consisting of two or more pleats folded to a radial depth Vof substantially 1/3 of its diameter. The bellows member has the cup-like conformation of the metal cup member I4, having an open end of relatively large diameter and which, in the assembled indicator seats e around the reduced inner end of the cup member I4, being provided with a relatively thick ange I9a surrounding its open end which seats securely against the internal shoulder I4a of the cup member I4, as clearly shown in Figure 4. At the opposite or outer end of the bellows member, there is formed a button-like knob Ib, yprojecting through a circular opening I1b at the center of the hinged plate I1, said opening being of a diameter substantially equal to the reduced neck portion of the button ISb, so that by forcing the latter therethrough it is securely attached to the plate. Obviously, thebellows member being made of rubber or like elastic materialyields readily to theassembly operation and likewise expands and contracts axially inv response to variations in pressureexerted internally or externally thereon.

Being? thus sealed within the retaining cup 'member I4, the bellows member forms a yieldable wall ofv a pressure chamber which communicates with the exhaust or pressure side of the cleaner through a short tube 20, .having one end iitting over a short nipple 2l anchored in the vertical web IIa of the indicator supporting bracket Il and the contacting end wall of the cup member I4, and its outer end fitted into a bore 22 cored in the rear wall of the exhaust outlet connections from the cleaner casing I. In this manner, the connection is made between the pressure chamber within the indicator and the entrance to the dirt bag 6, with the result that any change in air pressure within the bag is transmitted to the pressure chamber of the indicator. In short, Athe pressure within the indicator pressure chamber A-is always the same as that within the bag 6. 4Thus it follows that, as the pressure within the indicator chamber is increased beyond a predetermined minimum, the bellows member I9 will expand and this expansion transmitted to the f hinged plate I1, causes the same to swing forwardly toward the dotted line position shown in Figure 1y with its signal arm I8 ina horizontal position. A

But in exerting its pressure against the hinged plate I1, the bellows member or better, `the pressure which tends to expand the bellows member,

encounters an opposing pressure exerted on the plate by a coiled spring 23 which is carried on the4 bearing pin I6.` This coil spring is made up of a considerable number of turns of light wire and while itis coiled around the bearing pin I6 has a diameter large enough to permit it to slide freely along said pin. The endmost coils of the spring 23 terminate in straight end portions one of which bears against the horizontal web IIb of the supporting bracket II just below the spring, whereas the opposite end of the spring is adapted to en -A gage one of a series of tooth-like notches I1c cut in the inclined edge of a wide V-shaped notch formed in the upper edge portion of the hinged plate I1. The obvious purpose of this spring and notch arrangement is to provide a convenient method of regulating the force exerted by the spring upon the hinged plate I1. Thus, by shifting the plate engaging end of the spring from one notch I'1c to another, a slight increase or decrease in tension of theispring is obtained and this is suilicient to appreciably vary the action of the indicators so that each can be calibrated to the particular cleaner on which it is installed and thus insure uniform and accurate response to bag pressure conditions.

As heretofore stated, the indicator is mounted upon the top wall of the cleaner casing I, andis concealed beneath the rear portion of the motor cover 3. However, its exact location, as shown in Figure 2, is one offset to one side of the body of the cleaner and just inside of the line of contact between the bottom edge of the cover 3 and the top wall of the casing I.

Beneath the top wall Ia ofthe casing I, and extending transversely of the casing with a portion lying outside of and a portion inside of the cover 3is a chamber 24 formed by a short depending wall segment 24a integral with the top wall Ia of the casing, and a bottom closure `plate 24h. This chamber is comparatively shallow, and only large enough to accommodate the lower and horizontally extended end portion of the signal arm I8. As shown in Figure 2, a slot 25 formed in the top wall Ia, and elongated in a direction lengthwise of the casing, is located just inside the adjacent bearing edge of the cover 3, and through this slot the signal arm is extended.

Located outwardly from the slot 25, and beyond the bearing edge of the cover 3 is 'a circular opening or window 26 preferably having a transparent closure so as to prevent the entrance of dust and dirt therethrough. This window is so located that when the bellows member is fully expanded, as shown in dotted lines Figures 1 and 4, the target Ilia is positioned immediately below the windw, and thus visible from above by the opera or.

Thus, with the tension spring 23 adjusted to a predetermined minimum air pressure within the dirt bag, it is apparent that when a point is reached at which the increased air pressure in the bag overcomes the opposing spring pressure, the bellows member I9 willl expand and when the pressure reaches' a predetermined maximum,

the expansion of the bellows member brings the signal target I8a -beneath the window 26 as a warning to the operator to empty the contents of the bag.

Apart from the spring adjusting feature which permits the indicator to be properly regulated, there are other desirable and advantageous structural features to be mentioned and which contribute to its dependable performance. Due

. to the fact that the bellows chamber of the indicator has direct communication with the interior of the dust bag, it follows tliat dirt will find its way into the pressure chamber and hence provision is made for the detachable mounting of the bellows member in the cup member I4 and from the .hinged plate I1 so that it may be easily removed for cleaning purposes, this being ordinarily attended to by a service man and at regular intervals. Y

These features, among others, contributing to the compact and workmanlike design of the indicator, are set forth in the appended claims in which I claim:

1. In a pressure indicator, the combination of a supporting member having a recessed portion communicating with the spaceunder pressure, an axially expansible bellows member having an open end seating in said recessed portion to form a chamber sealed from the atmosphere, a signal member pivotally mounted on said supporting member and including a plate forming an abutment for said bellows member, the latter having a knob projecting from its plate abutting end and said plate having an opening to receive said knob, a spring acting on said plate adjacent its pivotal axis to oppose the expansion of said bellows member, and means for adjusting said spring to vary the tension exerted thereby.

2. In a bag pressure indicator .for suction cleaners, the combination of a rigid cup-shaped member adapted to be mounted on the casing of a cleaner, a bellows member of annular form seating within said cupped member to form a pressure chamber communicating with the pressure side of the fan of the cleaner, a signal member hinged to swing relative to said cup-shaped member comprising a hinged plate extending over the open end thereof and having an aperture therein, said bellows member bearing at its outer end against said plate and having a button-like enlargement adapted to 'be inserted through said aperture, a spring acting on said signal member to oppose its movement under the expansion of said bellows, said signal memk ber having a colored target movable into and out of signalling position with the expansion and contraction of said bellows member, said suction cleaner casing having a chamber beneath an upwardly facing wall thereof in which said target is movable .and a window in said chamber through which said target is visible in its signalling position.

3. In a bag pressure indicator for a suction cleaner, the combination of a supporting frame including a cup-shaped recess, an axially extensible bellows member fitting within said recess with its interior space communicating with the pressure side of the fan of said suction cleaner, a plate having hinged connection with said supporting member and extending over the opening to said recess and having detachable aperture and button connection with the adjacent end of said bellows member, a spring acting on said plate to oppose its movement under the expansion of said bellows, andga signal arm carried by said plate and movable therewith' into and out of signalling position.

4. In a pressure indicator for, suction cleaners, the combination of a supporting frame having a cup-shaped recess, an axially expansible bellows member seating within said recess and forming therewith a pressure chamber communicating with the space under pressure, a plate having hinged connection with said frame-and extending over said recess to provide an abutment ,for the free end of said bellows member; the latter having detachable connection with said plate, a spring acting on said plate at its point of hinged connection with said frame and acting to oppose its movement under the expansion of said bellows member, and a signal arm forming an in- 'tegral extension of said plate.

5. In a bag pressure indicator for suction cleaners, the combination of a supporting frame including a cup-shaped member, an axially eX- pansib'le bellows member substantially enclosed within said cup-shaped member and forming therewith a pressure chamber communicating with the space subject to varying pressure conditions, a spring-actuated cup-shaped member and having detachable connection with the free end of said bellows member, and a signal arm forming an extension of said plate remote from its hinged mounting.

6. In a pressure indicator for suction cleaners, the combination of a supporting frame having a cup-shaped recess, an axially expansible space subject to varying pressure conditions, a plate having hinged connection along one edge with said frame member and extending over the open end of said recess to form an abutment for the free end of said bellows member, the latter having a detachable fastening with the central portion of said plate, a spring acting on said plate to opposeI its movement by said bellows member, means for adjusting the tension exerted by said spring on said plate, and a signal arm integral with said plate and projecting from n edge thereof remote from its hinged connec- 7. In a bag pressure indicator for suction cleaners, the combination of a frame having a recessed portion, an axially expansible bellows member mounted within said recessed portion and forming therewith a chamber subject to variations in air pressure in the dirt bag of said cleaners, a signal member comprising a plate having hinged connection with said frame and adapted to form an abutment for the free end of Said bellows member, said hinged connection including a hinge pin, said plate having a series of stepped notches cut in the edge thereof adjacent to and extending parallel with said hinge pin, and a spiral coiled spring loosely mounted on said pin with one end adapted to bear against said frame and the other to engage one of said stepped notches.

8. In a bag pressure indicator for suction cleaners, the combination of a supporting frame, an axially extensible bellows member mounted on said frame and responsive to variations in pressurel within the dirt bag of said cleaner, a signal member comprising a plate having hinged connection with said frame, the latter supporting a hinge pin engaged by ears spaced apart along one edge of said plate, the latter having a series of notches of uniformly increasing depth formed in the edge thereof adjacent said pin, and a spiral coiled spring loosely surrounding said pin between said ears and adapted to have one end bear against said frame and the other to engage one of said notches, said'spring being adjustable lengthwise on said pin to permit the notch engaging endthereof to be shifted from one notch to another to vary the tension exerted by said spring.

HARRY B. WHITE. 

